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3 years ago

A pulley system has an efficiency of 74.2%. If you perform 200 J of work, how much useful work does the pulley perform?

1 answer:

7 0

<span>Efficiency is the measure of how efficient a process is. It is used to assess the ability of a process in avoiding waste energy, materials, money and time in doing a desirable output. It is calculated as;

Efficiency = useful energy ouput / total energy input</span>

<span>
.742 = useful energy / 200 J
Useful energy = 148.4 J <-----------OPTION B</span>

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What is the uncertainty of the position of the bacterium? express your answer with the appropriate units?

lbvjy [14]

For two un-related quantities, the Heisenberg uncertainty equations holds: the prduct of the two uncertainty quantities is greater than $\hbar/2$
Example of unrelated quantities are position and momentum, energy and time.
Thus
$\Delta x*\Delta p \ \textgreater \ \hbar/2$
Knowing the speed of the bacteria the uncertainty in its position is
$\Delta x \ \textgreater \ \hbar/(2 \Delta p) =\hbar/(2mv)$

4 0

3 years ago

a hiker walks 200 m west and then walks 100 m north in what direction is her resulting displacement draw to show your answer

Sliva [168]

Answer:

The direction of the displacement is in North-West.

Explanation:

Resultant displacement D is

$=\sqrt{(200)^{2} + (100)^{2} } \\=223.60m$

Here the direction is

$\Theta =tan^{^{-1}}\left ( \frac{100}{200} \right )\\\Theta =26.6^{o}$

Then the direction is $26.6^{o}$ North-west.

5 0

3 years ago

Imagine an alternate universe where all of the quantum number rules were identical to ours except m_{s} had three allowed values

marishachu [46]

Answer:

so in a given orbital there can be 3 electrons.

Explanation:

The Pauli exclusion principle states that all the quantum numbers of an electron cannot be equal, if the spatial part of the wave function is the same, the spin part of the wave function determines how many electrons fit in each orbital.

In the case of having two values, two electrons change. In the case of three allowed values, one electron fits for each value, so in a given orbital there can be 3 electrons.

5 0

3 years ago

A sample of gas in a syringe releases heat to its surroundings while the

blsea [12.9K]

Answer: b

Explanation:

When heat is released by the system i.e. system loses heat. So, we take it as negative -Q

When the work is done on the system then it is considered as negative work on the system i.e. -W

In this case, the plunger is pulled out, and work is done on the system. So, we take work as negative work -W

Correct option is b

3 0

3 years ago

Read 2 more answers

An ideal spring hangs from the ceiling. A 1.95 kg mass is hung from the spring, stretching the spring a distance d=0.0865 m from

uranmaximum [27]

Answer:

kinetic energy = 0.1168 J

Explanation:

From Hooke's law, we know that ;

F = kx

k = F/x

We are given ;

Mass; m = 1.95 kg

Spring stretch; d = x = 0.0865

So, Force = mg = 1.95 × 9.81

k = 1.95 × 9.81/0.0865 = 221.15 N/m

Now, initial energy is;

E1 = mgL + ½k(x - L)²

Also, final energy; E2 = ½kx² + ½mv²

From conservation of energy, E1 = E2

Thus;

mgL + ½k(x - L)² = ½kx² + ½mv²

Making the kinetic energy ½mv² the subject, we have;

½mv² = mgL + ½k(x - L)² - ½kx²

We are given L=0.0325 m

Plugging other relevant values, we have ;

½mv² = (1.95 × 9.81 × 0.0325) + (½ × 221.15(0.0865 - 0.0325)² - ½(221.15 × 0.0865²)

½mv² = 0.62170875 + 0.3224367 - 0.82734979375

½mv² = 0.1168 J

7 0

3 years ago